Switchboabd lamp



March 27, 1928. 1,664,228

H. P. SPARKES SWITCHBOARD LAMP Filed May '7, 1923 INVENTOR ATTORNEYPatented Mar. 27, 1928.

UNITED STATES PATENT OFFICE.

HARRY P. SPARKES, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SWITCHBOARD LAMP.

Application filed May 7,

My invention relates to switchboard lamps and particularly to signal andindicating lamps such as are used on switchboards employed in largepower stations and which indicate the condition of an electric circuit.

Switchboards of this character comprise relatively thick panels of slateor other insulating material upon which various instruments and circuitcontrolling switches are mounted. It has been a common practiceheretofore to provide signal lamps which were mounted in perforations inthe panel.

Because of the high voltages usually employed in illuminating the lamps,it was necessary to employ a lamp having a relatively long filamentwhich in turn necessitated a long cylindrical containing bulb.

Such bulbs are mounted in perforations in the panel and the filamentthereof lies with in the perforation and behind the front face of thepanel. A. lens visible from the front of the board serves to close theperforation and the mounting for the lens is usually provided withventilating openings to permit of the circulation of air in the openingin order to maintain the operating temperature of the lamp aslow aspossible. However, these ventilating devices have been found to beinadequate because of the heating effect of the extensive filamentclosely confined within the perforation in the panel and as aconsequence the operating temperature of the lamp is' increased to thepoint that its life is shortened. Replacement of the rel.- ativelyexpensive high voltage lamp increases the operating cost oftheswitchboard considerably.

One object of my invention is to provide a lamp for switchboard panelshaving a socket device forthe lamp that enables the use of standardautomobile lamps which operate on relatively low voltage andconsequently are not subject to the objectionable heating conditionsincident to lamps of relatively high voltage.

Another object of my invention is to provide a switchboard lamp where inthe resistor element for reducing the voltage of the lamp circuit servesto clamp the lamp socket to the switchboard.

Another object of my invention is to provide a switchboard panel lamphaving a hemispherical lens projecting from the front face of the panelthat is visible from both the front and the sides of the panel, thusrendering the lens visible from any point in the operating room in frontof the plane of the switchboard upon which the lamp is mounted andwherein the electric lamp extends into the lens.

Another object of my invention is to provide a switchboard panel lampwhich is inexpensive to manufacture and which may readily be assembledupon the panel, and which supports a standard lamp with its filament infront of the front face of the panel.

Another object of my invention is to provide a switchboard panel lampwherein a hemispherical lens is provided for protecting the lamp andwhich may readily be remove when it is desired to inspect or replace thelamp. Such lens may be of any desired color and a standard automobilelamp may be used without alteration.

These and other objects that will be made apparent throughout thefurther description of my invention are attained in the lamp devicehereinafter described and illustrated in the accompanying drawings,wherein Figure 1 is a perspective view of the switchboard lamp showingthe lens and attaching ring detached from the holder.

Fig. 2 is a longitudinal section through the lamp structure and Fig. 3is an end view of the lamp with the lens removed.

Referring to the drawings the lamp device includes an insulating sleeve,or bushing 4 constituting a lamp receptacle and, having threaded endsand which is inserted in the perforation or opening 5 extending from thefront to the rear of the panel 6. The ends of the bushing project beyondthe front and rear faces of the panel and the end projecting from thefront face of the panel is provided with longitudinal slots 7 preferably4 in number for the purpose of dividing the end into integral flexiblesections that may be pressed into engagement with a standard automobilelamp socket 8 for re taining it within the sleeve.

The standard automobile lamp socket comprises a cylindrical insulatingmember 9 that is secured within a metal sleeve 11 having twodiametrically opposite angular slots 12, one of which is shown,extending inwardly Serial No. 837,184.

element 26 for the purpose ofredueing the voltage to that required forthe lamp which is usually operated on (5 and 12 volts.

A lens socket 16 having a greater external diameter than the perforation5 in the panel is secured upon the slotted end of the sleeve 4 andserves to clamp the flexible sections of thesleeve i tightly against thesleeve 11 of V the lamp socket and tothereby retain it in any desiredposition. The interior bore 17 of the lens socket is enlarged to providea shoulder 18 for receiving and supporting a head 19 on thehemispherical lens 21.

The enlarged bore of the lens socket is provided with anannular groove22 for receiving and retaining spring 23 which is inserted within thegroove after the lens has been assembled in its socket. The spring 23 isprovided at its end with outwardly and for- Wardly turned extensions 2 kthat are adapted to be gripped by the thumb and finger of the operatorand moved toward one another when it is desired to release the lens fromits socket. When the ends 24: of the spring 23 are pressed together, thespring 23 is sufficiently contracted in diameter to permit it to bewithdrawn from the groove to release the lens. When the spring is inassembled position in the socket it expands into the groove 22 andengages the flange 19 and retains the lens within its socket.

A notch 25 is cut in the enlarged bore of the socket and extends intothe groove 22. This notch permits the insertion or the withdrawal of theextensions 24 of the spring 23.

The lamp socket just described is securely clamped in operative positionupon the panel by a threaded nut 27 that is mounted on the threaded endof-the sleeve 4 and which serves to support the resistance eleessary toprovide ventilating openings in the lens holder.

While I have described and illustrated only one embodiment of myinvention it will be apparent to those skilled in the art that variouschanges, substitutions, additions and omissions, modifications may bemade in the apparatus illustrated without departing from the spirit andscope of my invention as set forth in the appended claims.

' I claim as my invention:

1. A lamp for switchboard panels comprising a bushin adapted to extendthrough a perforation in the panel having threaded projecting ends, oneof which is slotted longitudinally for rendering it ex pansible andeontractible, a lamp socket Within the slotted end of the bushing for sosupporting a lampthat the filament thereof lies exteriorly of thebushing, a threaded lens socket co-operating with the slotted end of thebushing for clamping the socket within the bushing and for engaging thefront face.

of the panel, said lens socket and bushing also including means forcontracting the slotted end of the latter, a threaded nut on the otherend of the bushing for securing the bushing within the panel, a lens andmeans for securing the lens in the lens socket, said lens having aportion extending. beyond the socket and visible from the front and sideof the panel. g

2. A lamp for switchboard panels comprising a bushing adapted to extendthrough a perforation in the panel having threaded projecting ends, oneof which is tapered and is slotted longitudinally for rendering itexpansible and contractible, a lamp socket within the slotted end of thebushing, for so supporting a lamp that the filament thereof liesexteriorly of the bushing, a threaded lens socket co-operating withtheslotted end of the bushing for clamping the socket within the bushingand for engaging the front face of the panel, a threaded nut on theother end of the bushing for securing the bushing within the panel, alens and means for securing the lens in the lens socket, said lenshaving a cavity therein for receiving the lamp. v r

A lamp for switchboard panels com prising a flexible tubular memberextending through a perforation in the panel andhaving its ends threadedand extending beyond the front and rear faces of the panel, a'terminalsocket within the front end of the tubular member for receiving astandard elec tric lamp and so supporting it that thefilament extendsbeyond the end of the said member, a threaded lens socket adjustablymounted on a threaded portion of the 'tubular member and having meanscooperating with the said threaded portion for compressing the tubularmember into engagement with the terminal socketand thereby clamping thelatter within the tubular member, a threaded nut on the rear end of thesaid member for clamping it to the panel, a substantiall hemisphericallens mounted in the lens sociiet and enveloping the lamp and having itsmajor portion projecting from the socket and visible from the front andsides of the panel and means for securing the lens in the lens socket.

In testimony whereof, I have hereunto 10 subscribed my name this 9th dayof April, 1923.

HARRY P. SPARKES.

